The promoter elements of the-100 region, CCAAT box, and TATA box were found in the 5'-flanking region offish globin genes. The 5'-flanking and 5'-untranslated regions of the yellowtail Seriola quinqueradiata a-like globin gene were recombined with the chloramphenicol acetyltrans-ferase (CAT) gene to determine whether or not these sequences possess the function of a promoter. The recombinant plasmids were introduced into fish cell lines (GF, TO-2, and GCT), and signifi-cant CAT activity was detected. In the GF cell line, CAT activity was enhanced. This result suggests that the sequences from the fish globin gene possess promoter activity and play an impor-tant role in the regulation of gene expression in cultured fish cells. SV40 early promoter activity was also detected in the fish cell lines.